McQuay RCS015 Installation Manual

Installation and Maintenance Manual IM 738-2

RoofPak™ Singlezone Roof Mounted Heating and Cooling Units

RPS/RDT/RFS/RCS 015-135C

Group: Applied Systems

Part Number: IM 738

Date: June 2006

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Unit Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Compressor Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Gas Burner Nameplate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Hazard Identification Information . . . . . . . . . . . . . . . . . . . . . . . 3

Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Typical Component Locations . . . . . . . . . . . . . . . . . . . . . . . . . 6

Condenser Fan Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . 8

Refrigeration Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Control Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Controls, Settings, and Functions . . . . . . . . . . . . . . . . . . . . . 22

Mechanical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Ventilation Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Overhead Clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

IBC Seismic Compliant Units . . . . . . . . . . . . . . . . . . . . . . . . 30

Roof Curb Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Post and Rail Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Post and Rail Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Rigging and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Reassembly of Split Units . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

RPS/RDT Factory Split at Condensing Unit . . . . . . . . . . . . . 42

RFS/RCS Permanent Split Systems . . . . . . . . . . . . . . . . . . . 47

Unit Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Steam Coil Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Steam Piping Recommendations . . . . . . . . . . . . . . . . . . . . . 54

Steam Trap Recommendations . . . . . . . . . . . . . . . . . . . . . . . 55

Damper Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Cabinet Weather Protection . . . . . . . . . . . . . . . . . . . . . . . . . 58

Installing Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Installing Duct Static Pressure Sensor Taps . . . . . . . . . . . . . 59

Installing Building Static Pressure Sensor Taps . . . . . . . . . . 60

Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Field Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Field Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Preparing Unit for Operation . . . . . . . . . . . . . . . . . . . . . 65

Spring Isolated Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Relief Damper Tie-Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Adjusting Scroll Dampers . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

Adjusting Supply Fan Thrust Restraints . . . . . . . . . . . . . . . . 66

Sequences of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Fan Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

Economizer Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Mechanical Cooling Operation . . . . . . . . . . . . . . . . . . . . . . . 68

Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Unit Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Enthalpy Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

Hot Gas Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

SpeedTrol™ (N/A Unit Sizes 015C to 030C) . . . . . . . . . . . . 99

External Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Smoke and Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . 100

Smoke Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Freeze Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Entering Fan Temperature Sensor . . . . . . . . . . . . . . . . . . . 102

Duct High Pressure Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

MicroTech II™ Remote User Interface (UI) . . . . . . . . . . . . . 102

Variable Frequency Drive Operation . . . . . . . . . . . . . . . . . . 104

Convenience Receptacle/Section Lights . . . . . . . . . . . . . . . 104

DesignFlow™ Outdoor Air Damper Option . . . . . . . . . . . . . 104

Propeller Exhaust Fan Option . . . . . . . . . . . . . . . . . . . . . . . 107

Exhaust Fan On/Off Control . . . . . . . . . . . . . . . . . . . . . . . . . 109

Ultraviolet Lights Option . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

Ultraviolet Light Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 111

Check, Test, and Start Procedures . . . . . . . . . . . . . . 112

Servicing Control Panel Components . . . . . . . . . . . . . . . . . 112

Before Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

Power Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Fan Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Economizer Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

Compressor Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Scroll Compressor Rotational Direction (sizes 15 to 105) . . 114

Oil Pressure (sizes 115 to 135C only) . . . . . . . . . . . . . . . . . 115

Heating System Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Air Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Sheave Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Drive Belt Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

Mounting and Adjusting Motor Sheaves . . . . . . . . . . . . . . . 119

Final Control Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Servicing Control Panel Components . . . . . . . . . . . . . . . . . 126

Planned Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Unit Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

Gas Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Bearing Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

Setscrews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129

Supply Fan Wheel-to-Funnel Alignment . . . . . . . . . . . . . . . 130

Refrigerant Leaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Refrigerant Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Servicing Refrigerant Sensors or Switches . . . . . . . . . . . . . 131

Winterizing Water Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

Control Panel Components . . . . . . . . . . . . . . . . . . . . . . . . . 132

Replacement Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Service and Warranty Procedure . . . . . . . . . . . . . . . . 137

Scroll Compressor (sizes 15 to 105C) . . . . . . . . . . . . . . . . . 137

Reciprocating Compressors (sizes 115 to 135C) . . . . . . . . 137

All Compressors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

Limited Product Warranty (North America) . . . . . . 139

Exceptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Sole Remedy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Rooftop Equipment Warranty Regist. Form . . . . . 140

Introduction

This manual provides general information about the “C” vintage McQuay RoofPak applied rooftop unit, models RPS, RDT, RFS, and RCS. In addition to an overall description of the unit, it includes mechanical and electrical installation procedures, commissioning procedures, sequence of operation information, and maintenance instructions. For further information on the optional forced draft gas-fired furnace, refer to Bulletin No. IM 684 or IM 685.

The MicroTech II applied rooftop unit controller is available on “C” vintage applied rooftop units. For a detailed description of the MicroTech II components, input/output configurations, field wiring options, requirements, and service procedures, see IM 696-3. For operation and information on using and programming the MicroTech II unit controller, refer to the appropriate operation manual (see Table 1).

For a description of operation and information on using the keypad to view data and set parameters, refer to the appropriate program-specific operation manual (see Table 1).

Table 1: Program specific rooftop unit operation literature

Rooftop unit control configuration

VFDs Vendor IM manuals

Discharge Air Control (VAV or CAV) OM 137-2

Space Comfort Control

(CAV-Zone temperature control)

Operation manual bulletin

number

OM 138-2

Unit Nameplate

The unit nameplate is located on the outside lower right corner of the main control box door. It includes the unit model number, serial number, unit part number, electrical characteristics, and refrigerant charge.

On units that utilize the tandem compressor design, each compressor includes an individual nameplate along with a nameplate identifying the tandem compressors.

Gas Burner Nameplate

On units that include gas heat, the nameplate is located on the lower right corner of the main control box door. It includes the burner model number, minimum/maximum input, maximum temperature rise, and minimum cfm.

On units that utilize the tandem scroll compressor design, each compressor includes an individual nameplate along with a nameplate identifying the tandem compressors.

On units that utilize the tandem reciprocating design, each compressor includes an individual nameplate.

Hazard Identification Information

WARNING

Warnings indicate potentially hazardous situations, which can result in property damage, severe personal injury, or death if not avoided.

CAUTION

Cautions indicate potentially hazardous situations, which can result in personal injury or equipment damage if not avoided.

Compressor Nameplate

On units with a single compressor on each circuit, the compressor includes one compressor nameplate.

McQuay IM 738-2 3

Introduction

Figure 1: Nomenclature

R P S – 030 C S E

RoofPak

Unit configuration P = Heating, mechanical cooling F = Heating, future mechanical cooling C = Condensing section only D = Draw through cooling

Blow through cooling = S Draw through cooling = T

Nominal capacity (tons) RPS, RFS, RCS, RDT: 015, 018, 020, 025, 030, 036, 040, 045, 050, 060, 070, 075, 080, 090, 105, 115, 125, 135

Heat medium A = Natural gas E = Electric S = Steam W = Hot water Y = None (cooling only)

Cooling coil size S=Standard (low airflow) L =Large (high airflow)

Design vintage

4 McQuay IM 738-2

Unit Description

Figure 2: RPS/RDT/RFS/RCS unit

Introduction

R P S / R D T

R F S

R C S

McQuay IM 738-2 5

Introduction

Typical Component Locations

Figure 2 shows an RPS/RDT/RFS/RCS unit. Figure 3 shows a typical RPS unit with the locations of the major components.

Figure 3: Typical component locations—RPS units

Top View

Outside and return air dampersa

Side View

Exhaust hood

Bottom return air opening

Filter section

Supply air fan

Figure 4 on page 7 shows a typical RDT unit with the locations of the major components.

These figures are for general information only. See the project’s certified submittals for actual specific dimensions and locations.

Bottom discharge air opening

Power and control entrances

Evaporator coil

Discharge plenum (main control panel)

Optional back return opening

Return air

Return airReturn air fan

Outside air louvers

Heat section (natural gas, oil, steam, hot water, electric

Air cooled condenser

6 McQuay IM 738-2

Figure 4: Component locations—RDT units

Top View

Introduction

Bottom supply air opening

1.50 MPT drain

Bottom return opening

Side View

Return air plenum

Exhaust dampers

Optional back return air opening

Return air fan

Optional outside & return air dampers

Filter section

Outside air louvers (both sides)

Control entrances 7/8" dia K.O.

DX coil section

Evaporator coils

Power entrances 3" dia K.O.

Supply fan section

McQuay IM 738-2 7

Introduction

Condenser Fan Arrangement

Table 2 shows the condenser fan numbering conventions and locations for each unit size.

Table 2: Condenser fan arrangement

Unit size Refrigerant circuit Arrangement Unit size Refrigerant circuit Arrangement

COND

015C 018C 020C

1 or 2

AHU

075C 080C 090C

025C 030C 1 or 2

036C 040C

045C 050C

060C 070C

105C

115 C

1 125C 135C

8 McQuay IM 738-2

Introduction

Refrigeration Piping

This section presents the unit refrigeration piping diagrams for the various available configurations.

Figure 5: Circuit schematic

A - Compressor (1, 2, or 3 per circuit)† B - Discharge line †

Figure 6: Condenser piping, scroll compressors, one to three compressors per circuit are provided (015 to 105C)

Legend

1 - Discharge shut-off valve—Circuit #1 2 - Liquid shut-off valve—Circuit #1 3 - Liquid shut-off valve—Circuit #2 4 - Discharge shut-off valve—Circuit #2

C - Condenser coil † D - Evaporator coil* E - Manual shutoff valve† F - Filter-drier* G - Liquid line solenoid valve* H - Sightglass* I - Liquid line*† J - Suction line K - Thermal expansion valve* L - Distributor* M - Hot gas bypass and solenoid valve (optional)*† N - Hot gas bypass lines (optional)* †

*Supplied on RFS units †Supplied on RCS units

Compressor #1

Discharge lines Circuit #1 Circuit #2

Compressor #3

Liquid lines Circuit #1 Circuit #2

Compressor #4

Compressor #2

Optional hot gas bypass lines Circuit #1 Circuit #2

Suction lines Circuit #1 Circuit #2

McQuay IM 738-2 9

Introduction

Figure 7: Condenser piping, four reciprocating compressors (115 to 135C)

Legend

1 - Discharge Line Service Valve 2 - Discharge Muffler 3 - High Pressure Relief Valve 4 - Liquid Line Manual Shut-off Valve 5 - Suction Line Service Valve

10 McQuay IM 738-2

Figure 8: Air handler piping (flat DX)

circu

Legend

1 - Filter-drier 2 - Liquid line solenoid valve 3 - Sightglass 4 - Hot gas bypass and solenoid valve (optional) 5 - Thermostatic expansion valve 6 - Distributor

Introduction

Figure 9: Air handler piping (staggered DX)

Legend

1 - Filter-drier 2 - Liquid line solenoid valve 3 - Sightglass 4 - Hot gas bypass and solenoid valve (optional) 5 - Thermostatic expansion valve 6 - Distributor

Liquid line circuit #1

Optional hot gas bypass line circuit #1 circuit #2

Air handler section

Condenser section

Circuit #1

Circuit #2

Liquid line circuit #2

Suction line circuit #1

it #2

McQuay IM 738-2 11

Introduction

Control Locations

Figure 10 (RPS Units) and Figure 11 on page 13 (RDT Units) show the locations of the various control components mounted throughout the units. See “Control Panel” on page 14 for the locations of control components mounted in control panels.

Figure 10: Control locations—RPS units

FS1

SD2

(optional)

Return air

economizer

C19

RAT

Filter

section

Supply

fan

section

LT11

(opt io nal )

OAT

S11, REC11

(optional)

Heat

section

OAE

ACT3

ACT6 (optional)

RAE (optional)

section

LT10

S10, REC10

PC5

Additional information is included in Table 3 on page 22 and the wiring diagram legend, which is included in “Wiring Diagrams” on page 71.Components mounted in the blowthrough section are located in the same position within the draw-through section.

SC11, 12 (optional)

C11, 12 (optional)

SV1

SV5 (optional)

SV6 (optional)

ACT5 (optional)

HP1-2, HP3-4 (optional)

LP1-2

HTR1-2, HTR3-4 (optional)

SV2

Disc harge

HL22

plenum section

EFT

(optional)

Condensor

section

SD1

PC7

DAT (optional)

VM1

(optional)

12 McQuay IM 738-2

Figure 11: Control locations—RDT units

section

Filter

section

Economizer

return air

Heat

section

Supply fan

discharge

plenum

section

Condenser

section

SC11, 21 (optional)

SV1, 2

Introduction

C11, 21 (optional)

HP1-2, LP1-2 HTR1-2, U1/U2 HP3-4 (optional) HTR3-4 (optional)

C19, 20

(optional)

RAT

LT11 (optional)

S11, REC11

SD2

(optional)

RAE

(optional)

ACT3

ACT6

PC5

OAE

OAT

VM1

(optional)

FS1

(optional)

DAT

LT10 (optional)

S10, REC10 (optional)

SD1 (optional)

SV5, 6 (optional)

McQuay IM 738-2 13

Introduction

Control Panel

The unit control panels and their locations are shown in the following figures. These figures show a typical unit

Figure 12: Control panel locations

Prop exhaust (optional)

not shown)

(

VFDs, line reactors, and

manual bypass (optional)

Electric heat control panel (optional)

configuration. Specific unit configurations may differ slightly from these figures depending on the particular unit options.

Supply fan section

Condenser section

Main control panel

14 McQuay IM 738-2

Figure 13: Typical main control panel, 015 to 040, 460 volt

Introduction

See separate

detail, page 17.

McQuay IM 738-2 15

Introduction

Figure 14: Typical main control panel, 045 to 075, 460 volt

See separate

detail, page 17.

16 McQuay IM 738-2

Figure 15: Typical main control panel, 080 to 135, 460 volt

Introduction

Figure 16:

McQuay IM 738-2 17

Introduction

Figure 17: Typical gas heat panel, 1000 MBH Figure 18: Typical propeller exhaust panel, 3 fans, 460 volt

R22

TD10

R20

R23 R21

LS2

LS1

Figure 19: VFD bypass panel, 40 HP, 460 volt)

FSG

FSG Tim

18 McQuay IM 738-2

Figure 20: RCS control panel with MicroTech II, 015 to 040C

Figure 21: RCS control panel with MicroTech II, RPS 045 to 075C

Introduction

Figure 22: RCS control panel with MicroTech II, RPS 080 to 135C

McQuay IM 738-2 19

Introduction

Figure 23: Electric heat panel, sizes 15 to 40C

FB33 FB32 FB31

M33 M32 M31

FB43 FB42 FB41

M41 M42 M41

SR2

SR3

SR1

TB11

Figure 25: Electric heat panel, sizes 80 to 135

FB31FB32FB33

M31M32M33

FB34FB44

M34M44

FB41FB42FB43

M41M42M43

H53

TB11

PB3

Figure 24: Electric heat panel, sizes 45 to 75C

FB31FB32FB33 M31M32M33

FB41FB42FB43

M42

M41M43

GLG3

DS3

H53

TB11

GLG3

DS3

20 McQuay IM 738-2

Figure 26: Harness plug connector detail

RATS OATSDATS

FP1 OPEN1EPTS

AFD10 AFD20

SV12 SV56

ACT3 OPEN2

OAE PC7PC5

Introduction

HL22 OPEN3

GSHT1 GSHT2

SD1 SD2

DFRH DFLH OPEN4

COMP1 COMP2

COMP3 COMP4

COMP6COMP5

LT11LT1 0

LT OP1 LT OP2

McQuay IM 738-2 21

Introduction

Controls, Settings, and Functions

Table 3 below lists all of the unit control devices and associated information.

Table 3: Controls, settings, and functions

Symb

CS1 &

DAT

DHL

EFT

FP1, 2

FS1

HP1,

3 & 4

LP1, 2

MCB

MP1–

OAE

OAT

PC5

Description Function

Switch (toggle), refrigerant circuit

Discharge air temperature sensor

Duct high limit switch

Entering fan air temperature sensor

Evaporator frost protection

Freezestat

High pressure control

Low pressure control

Main control board Processes input information

Compressor motor protector

Enthalpy control (electromechanical)

Enthalpy control (electronic)

Outside air temperature sensor

Dirty filter switch Senses filter pressure drop

Shuts off compressor control circuits manually

Senses discharge air temperature

Prevents excessive VAV duct pressures; shuts off fan

Senses entering fan air temperature

Senses low refrigerant temperature

Shuts off fans, opens heating valve, and closes outdoor damper if low air temperature at coil is detected Stops compressor when refrigerant discharge pressure is too high

Stops compressor when suction pressure is too low (used for pumpdown)

Senses motor winding temperature, shuts off compressor on high temperature. Notes:

1.Unit size 018C compressors include internal motor protector.

2.Unit sizes 020C–036C, circuit #1 compressors include internal motor protector (refer to unit wiring diagram).

Returns outside air dampers to minimum position when enthalpy is too high

Returns outside air dampers to minimum position when outside air enthalpy is higher than return air empalthy (use RAE)

Senses outside air temperature

Rese

N/A

Auto

N/A

Auto

Manu

al (relay latche

Auto Compressor

N/A

Auto

3400

ohms

Auto

N/A N/A N/A

Auto

Location Setting Range Differential Part no.

Main control

panel

Discharge air

section

Main control

panel

Inlet of supply

fan

Return bends

of evaporative

coil

Heating

section

Compressor

Main control

box

Compressor

junction box

Economizer

section

Economizer

section

First filter

section

N/A N/A N/A 01355000

N/A N/A

3.5" w.c

(871.8 Pa)

N/A N/A

Opens at

30°F

Closes at

45°F

38°F (3°C)

or as

required

See page

131.

See page

131.

N/A N/A N/A

9 K–18 K

ohms

“B” or as required

Fully CW

past “D”

(when used

with RAE)

As required

0.05–5.0" wc (12.5–1245.4

Pa)

N/A N/A

35°F–45°F (2°C–7°C)

N/A

700 ohms cold N/A

A–D

A–D N/A

.05-5" wc

(12.5–1245.4

Pa)

.05" wc

(12.5 Pa),

fixed

12°F (7°C),

fixed

100 psi

(689 kPa)

25 psi

(172 kPa)

Temperature:

3.5°F (2°C) Humidity:

5% fixed

.05" wc

(12.5 Pa)

06000470

06549380

06000470

07250190

06583000

04735612

047356111

06000610

04469150

03070670

04926220

06000470

06549380

22 McQuay IM 738-2

Table 3: Controls, settings, and functions (continued)

Symb

PC6

PC7

PS1,

RAE

RAT

SD1

SD2

SPS1

SPS2

SV1,

SV5,

Description Function

Dirty filter switch Senses filter pressure drop

Airflow proving switch

Pumpdown switch Used to manually pump down

Return air enthalpy sensor

Return air temperature sensor

Smoke detector, supply air

Smoke detector, return air

Static pressure sensor duct #1

Static pressure sensor duct #2

Static pressure sensor: building (space) pressure

Solenoid valve (liquid line)

Solenoid valve (hot gas bypass)

System switch

ON-OFF-AUTO switch

Senses supply fan pressure to prove airflow

compressor

Used to compare return air enthalpy to outside air enthalpy (used with OAE)

Senses return air temperature

Initiates unit shutdown if smoke is detected

Converts static pressure signals to voltage signals

Converts static pressure signals to voltage signals and sends them to MicroTech II controller

Converts static pressure signals to voltage signals.

Closes liquid line for pumpdown

Closes hot gas bypass line for pump-down

Shuts off entire control circuit (except crankcase heaters)

Used to manually switch unit

Rese

Auto

N/A

ManualDischarge air

ManualReturn air

N/A

Location Setting Range Differential Part no.

Final filter

section

Supply fan

section

Condenser control box

Economizer

section

Return air

section

Main control

box

Main control

box

Main control

box

Condenser

section

Condenser

section

Main control

box

Main control

box

Introduction

As required

.10" wc (25

Pa)

N/A N/A N/A 01355000

N/A N/A N/A

N/A N/A

N/A N/A N/A 04925001

N/A

N/A N/A N/A

N/A N/A N/A 111011001

N/A N/A N/A

.05-5" wc

(12.5–1245.4

Pa)

.03-1.40" wc

(7.5–348 Pa)

0–5" wc (0–1245.4 Pa) 1–6 V (dc) out

-025–0.25" wc

(-62.3–62.3 Pa)

1–5 V (dc) out

.05" wc

(12.5 Pa)

.03" wc

(7.5 Pa),

fixed

N/A

06549380

06001580

04926220

06000470

04954500

00135500

See parts

catalog

FanTrol

The FanTrol, provided on all units, is a method of head pressure control that automatically cycles the condenser fans in response to ambient air temperature. This feature maintains

head pressure and allows the unit to run at low ambient air temperatures.

RPS/RDT and RCS units have two independent refrigerant circuits with one to four condenser fans being controlled independently by the ambient air temperature of each circuit.

Table 4: R-22 FanTrol setpoints in °F with MicroTech II controls

RPS RCS RDT RPR

015 to 020C0 5 60 5 ———— 025 to 030C0 5 65 5 ————

0360 5 70 5 ————

045 to 045C0 5 65 5 ————

0500 5 60 5 ———— 0600 5255705—— 0700 5405705——

075 to 090C 0 5 65 5 75 5 0 5

1050505585705 1150505555755 1250 5655355805 1350 5555255655

Setpoint Differential Setpoint Differential Setpoint Differential Setpoint Differential

B05 B06 B07 B08

McQuay IM 738-2 23

Degrees Farenheit

Introduction

Table 5: R-407C FanTrol setpoints in °F with MicroTech II controls

RPS, RCS, RDT

Setpoint Differential Setpoint Differential Setpoint Differential Setpoint Differential

015 0 5 60 5 018 to 020C0505———— 025 to 036C0 5 65 5 ————

040 0 5 60 6

0450 5 55 5 ————

050 0 5 50 5 — —

0600 5155705——

0700 5305705——

0750 5655755 0 5 080 to 090C 0 5 65 5 75 5 0 5

1050505525705

1150505455755

1250 5555305805

1350 5455205655

B05 B06 B07 B08

Degrees Farenheit

24 McQuay IM 738-2

Mechanical Installation

Note – The installation of this equipment shall be in accordance

with the regulations of authorities having jurisdiction and all applicable codes. It is the responsibility of the installer to determine and follow the applicable codes. Low head pressure may lead to poor, erratic refrigerant feed control at the thermostatic expansion valve. The units have automatic control of the condenser fans which should provide adequate head pressure control down to 50°F (10°C) provided the unit is not exposed to windy conditions. The system designer is responsible for assuring the condensing section is not exposed to excessive wind or air recirculation.

CAUTION

Sharp edges on sheet metal and fasteners can cause personal injury. This equipment must be installed, operated, and serviced only by an experienced installation company and fully trained personnel.

Receiving Inspection

When the equipment is received, all items should be carefully checked against the bill of lading to be sure all crates and

Figure 27: Service clearances

72"

(1829 mm)

cartons have been received. If the unit has become dirty during shipment (winter road chemicals are of particular concern), clean it when received.

All units should be inspected carefully for damage when received. Report all shipping damage to the carrier and file a claim. In most cases, equipment ships F.O.B. factory and claims for freight damage should be filed by the consignee.

Before unloading the unit, check the unit nameplate to make sure the voltage complies with the power supply available.

Unit Clearances

Service Clearance

Allow an approximate service clearance as indicated in Figure 27. Also, McQuay recommends providing a roof walkway to the rooftop unit as well as along two sides of the unit that provide access to most controls and serviceable components.

60"

(1524 mm)

Roof walkway

To roof access

location

60"

(1524 mm)

96"

(2438 mm)

Varies with unit arrangement

Refer to certified drawing & note.

Ventilation Clearance

Below are minimum ventilation clearance recommendations. The system designer must consider each application and provide adequate ventilation. If this is not done, the unit will not perform properly.

Unit(s) surrounded by a screen or a fence:

60"

(1524 mm)

Legend:

A = Return air section B = Filter section C = Cooling section D = Cooling/supply fan section E = Heat section F = Discharge plenum section

The bottom of the screen or fence should be at least 1 ft. (305 mm) above the roof surface.

2 The distance between the unit and a screen or fence should

be as described in Figure 27.

3 The distance between any two units within a screen or

fence should be at least 120" (3048 mm).

McQuay IM 738-2 25

Mechanical Installation

Unit(s) surrounded by solid walls:

1 If there are walls on one or two adjacent sides of the unit,

the walls may be any height. If there are walls on more than two adjacent sides of the unit, the walls should not be higher than the unit.

2 The distance between the unit and the wall should be at

least 96" (2438 mm) on all sides of the unit.

3 The distance between any two units within the walls should

be at least 120" (3048 mm).

Do not locate outside air intakes near exhaust vents or other sources of contaminated air.

If the unit is installed where windy conditions are common, install wind screens around the unit, maintaining the clearances specified (see Figure 28). This is particularly important to prevent blowing snow from entering the outside air intake and to maintain adequate head pressure control when

Figure 28: Overhead clearance

Overhead canopy

mechanical cooling is required at low outdoor air temperatures.

Overhead Clearance

1 Unit(s) surrounded by screens or solid walls must have no

overhead obstructions over any part of the unit.

2 The area above the condenser must be installed

unobstructed to allow vertical air discharge.

3 The following restrictions must be observed for overhead

obstructions above the air handler section (see Figure 28):

a There must be no overhead obstructions above the

furnace flue, or within 9" (229 mm) of the flue box.

b Overhead obstructions must be no less than 96"

(2438 mm) above the top of the unit.

c There must be no overhead obstructions in the areas

above the outside air and exhaust dampers that are farther than 24" (610 mm) from the side of the unit.

24" (610 mm) maximum

96" (2438 mm)

minimum,

top of unit to

permanent

overhead

obstruction

9" (229 mm) minimum to flue box, typical all sides

Flue box

24" (610 mm) maximum

26 McQuay IM 738-2

Mechanical Installation

Roof Curb Assembly and Installation

Locate the roof curb and unit on a portion of the roof that can support the weight of the unit. The unit must be supported to prevent bending or twisting of the machine.

If building construction allows sound and vibration into the occupied space, locate the unit over a non-critical area. It is

the responsibility of the system designer to make adequate provisions for noise and vibration in the occupied space.

WARNING

Mold can cause personal injury. Some materials such as gypsum wall board can promote mold growth when damp. Such materials must be protected from moisture that can enter units during maintenance or normal operation.

Install the curb and unit level to allow the condensate drain to flow properly and allow service access doors to open and close without binding.

Figure 29: RCS roof curb assembly

6 "

" Z Z "

6 "

1 . U n i t B a s e

2 . G a l v a n i z e d C u r b 3 . G a l v a n i z e d C u i r b C o v e r 4 . 2 x 4 N a i l e r S t r i p 5 . R i g i d I n s u l a t i o

6 "

6 . C a n t S t r i p ( n o t f u r n i s h e d ) 7 . F l a s h i n g ( n o t f u r n i s h e d ) 8 . C u r b G a s k e t i n g 9 . I n s u G a l v a n i z e d C u r b ( n o t f u r n i s h e d ) 1 0 . R o o f i n g M a t e r i a l ( n o t f u r n i s h e d )

n ( n o t f u r n i s h e d )

l a t i o n b e t w e e n

Integral supply and return air duct flanges are provided with the RPS/RFS roof curb, allowing connection of duct work to the curb before the unit is set. The gasketed top surface of the duct flanges seals against the unit when it is set on the curb. These flanges must not support the total weight of the duct work. See “Installing Ductwork” on page 58for details on duct connections. It is critical that the condensate drain side of the unit be no higher than the opposite side.

Assembly of a typical RPS/RDT roof curb is shown in Figure 30 on page 28. Parts A through K are common to all units having bottom return openings. Depending on the unit length, Parts L and M may be included with the roof curb kit to create the correct overall curb length.

Figure 29 shows the assembly of the RCS roof curb.

RCS unit size

015C–030C 31.0 787

6 "

D e t a i l C

1 0

036C & 040C 94.0 2057

045C–060C 62.0 1575 070C–105C 100.0 2540 115C–135C 120.0 3048

in. mm

“ZZ”

RCS Assembly instructions

1 Set curbing parts “A” (Figure 29) in place making sure that

the orientation complies with the assembly instructions. Check alignment of all mating bolt holes.

2 Bolt curbing parts together using fasteners provided.

3 Curb must be level from side to side and over its length.

4 Weld curbing in place. Caulk all seams watertight and

insulate between channels.

5 Flash curbing into roof as shown in Detail C.

RPS/RDT Assembly instructions

1 Set curbing parts A through K per dimensions shown over

roof opening or on a level surface (see Figure 30 on page 28). Note location of return and supply air openings.

2 If applicable, set other curbing parts (D, L, M, etc.) in place

making sure that the orientation complies with the assembly instructions (see Detail A). Check alignment of

3 Bolt curbing parts together using fasteners provided.

Tighten all bolts finger tight.

4 Square entire curbing assembly and securely tighten all

bolts.

5 Position curb assembly over roof openings. Curb must be

level from side to side and over its length. Check that top surface of the curb is flat with no bowing or sagging.

6 Weld curbing in place. Caulk all seams watertight. Remove

backing from 0.25" (6 mm) thick × 1.50" (38 mm) wide gasketing and apply to surfaces shown by cross-hatching.

7 Flash curbing into roof as shown in Detail B.

8 Parts E and F are not required on units with no return shaft

within the curb perimeter.

9 Parts G and H are not required on units with no supply shaft

within the curb perimeter.

10 Be sure that electrical connections are coordinated (see

Figure 36).

all mating bolt holes.

McQuay IM 738-2 27

Mechanical Installation

Figure 30: RPS/RFS roof curb assembly

28 McQuay IM 738-2

Mechanical Installation

Table 6: Roof curb assembly dimensions

Unit size Fan

None 24.0 610 82.0 2083 6.8 173 1.5 38 015C–030C 45.9 1165 20.0 508

015–040C

045C–075C All units 38.0 965 87.0 2210 8.8 222 3.5 89 105C—135C 113 2870 46.0 1168

80C–135C All units 62.0 1575 87.0 2210 8.8 222 3.5 89

Note: These dimensions do not apply to units with energy recovery wheels.

(2) 15” FC 24.0 610 82.0 2083 6.8 173 1.5 38

30" AF 30.0 762 76.0 1930 6.8 173 4.5 114 045C–075C 77.0 1956 28.0 712 40" AF 36.0 914 78.0 1981 14.8 376 3.5 89 80C–90C 113 2870 38.0 965

“X” “Y” “XX” “YY”

in mm in mm in mm in mm in mm in mm

Unit size

036C and

040C

“Z” “W”

94.0 2388 20.0 508

McQuay IM 738-2 29

Mechanical Installation

IBC Seismic Compliant Units

It is important to follow these installation instructions for all IBC Seismic compliant McQuay Rooftop units.

IBC Seismic compliant McQuay Rooftop units can be mounted to either a roof curb or a post and rail setup. If using a roof curb, it must be specifically designed for seismic restraint and be IBC seismic compliant (spring isolated or non-isolated type seismic roof curbs are available). Typical construction of a seismic rated roof curb is from structural steel framing and contains seismic hold down brackets for attachment of the rooftop unit (see Figure 31). Post and rail arrangements rated for seismic applications are also available (spring isolated or non-isolated).

IMPORTANT: An acceptable IBC seismic installation provides a direct positive attachment to both the building structure and the roof mounted equipment.

Refer to the roof curb manufacturer’s submittal drawings for actual roof curb assembly, attachment details and rigging instructions for both roof curb and post and rail arrangements.

Figure 31: Typical seismic roof curb (spring isolated)

Roof Curb Arrangement

1 Set the rooftop unit on the roof curb (McQuay Rooftop

units are designed to overhang from the roof curb).

2 Adjust the seismic hold down brackets so they come into

contact with the unit base per Figures 32 and 33 on page

31.

a The seismic hold down brackets should be adjustable

and accommodate the overhang of the rooftop unit.

b If the hold down bracket cannot reach the unit base, use

a shim spacer. See Figure 33 on page 31.

3 Weld each seismic hold down bracket (and shim spacer, if

required) to the unit base as shown in the acceptable weld zone detail in Figure 32 on page 31.

CAUTION

When welding unit to the curb, do not damage wiring (control panel side). Weld ONLY in the specified zone in the acceptable weld zone (see Figure 32 on page 31). Welding must comply with weld fillet size, etc. as indicated in Figure 32 on page 31.

Note – High temperature insulation is installed at the factory to

allow for field welding along the lower front edge region of the unit base.

Duct opening

Seismic hold down brackets

Structural steel frame

Seismic hold down brackets

Spring isolator

30 McQuay IM 738-2

+ 114 hidden pages